(navigation image)
Home American Libraries | Canadian Libraries | Universal Library | Community Texts | Project Gutenberg | Children's Library | Biodiversity Heritage Library | Additional Collections
Search: Advanced Search
Anonymous User (login or join us)
Upload
See other formats

Full text of "Text Book Of Mechanical Engineering"

APPENDIX   II.

(THIRD    EDITION.)

CHAPTER I.

Pp. 3 and 42. Remelting of Cast Iron.—Experiments
made by Fairbairn in 1853, by melting Eglinton hot-blast pig up
to eighteen times, shewed that while at first there seemed to be
some improvement, there was a deterioration in the later meltings,
the iron becoming white and hard. Chemical examinations then
made by Snelus, and lately repeated by Mr. T. Turner cm* the original
pieces (lent by Prof. Unwin) indicate that the action is one of
oxidation, resembling that of the puddling furnace or Bessemer
converter.

MR. THOS. TURNER'S ANALYSIS.

Number
	Total

of melting.
	Carbon.

I
	2*67

8
	2'97

12
	2*94

H
	2-98

15
	2-87

1 6
	2-88

Combined Carbon.
	Silicon.
	Sulphur.
	Mangan.
	Phosp.

•25
	4-22
	•03
	175
	*47

•08
	3*21
	'OS
	•58
	"53

•85
	2-52
	'll
	'33
	'55

I'3I
	2-18
	•13
	*23
	•56

175
	1*95
	•16
	•    'I?
	•5*

2 '00
	r-88
	'20
	'12
	•61

P, 3. Moulding Sand.—Floor sand may have 6 parts by
weight of old sand to 2 of new sand and half a part of coal dust;
fadng sand, 6 of old sand to 4 of new sand and one of coal dust
Too much burnt sand, even if ground up, cakes when re-used, and
causes the metal to boil. Too much wetting is as bad as too
little, but the requisite consistency may be roughly tested by grasp-
ing a handful of the sand, which should just retain its shape when
the hand is again opened, A more scientific method is used by
Mr. Bagshaw,.who prepares bars of sand in moulds, by light
pressure, 12 inches long and i inch square, which he slowly pro-